Antibacterial activity and recyclability of magnetically recoverable ag-modified MnFe2O4/rGO Photocatalyst synthesized utilizing plant leaf extract

In this study, we focus on the environmental friendliness of Ag-modified MnFe 2 O 4 /rGO nanocomposites, which function as magnetically separable and reusable photocatalysts for rapidly inactivating Escherichia coli (E.coli) . The photocatalysts were successfully synthesized using an environmentally friendly green synthesis route using Moringa oleifera (MO) and Amaranthus viridis (AV) leaf extracts as natural reducing and stabilizing agents. Magnetic measurements demonstrated superparamagnetic behavior with high saturation magnetization, confirming the magnetic separability of the nanocomposites. Photocatalytic investigation revealed that the MnFe 2 O 4 /rGO/Ag nanocomposites exhibited superior photocatalytic and antibacterial performance, achieving rapid and complete (100%) inactivation of E. coli under UV irradiation compared with MnFe 2 O 4 and MnFe 2 O 4 /rGO. Electrochemical impedance spectroscopy (EIS) further supported the enhanced interfacial charge-transfer characteristics of the Ag-modified composite, consistent with more favorable charge-carrier transport within the heterostructure. The enhanced activity is attributed to the synergistic interaction among MnFe 2 O 4 , rGO, and Ag, which promotes efficient charge separation and facilitates reactive oxygen species (ROS) generation. Furthermore, the nanocomposites maintained excellent recovery and reusability, retaining high antibacterial efficiency over three consecutive cycles. These results demonstrate that MnFe₂O₄/rGO/Ag nanocomposites are promising, sustainable, and magnetically recoverable photocatalysts for water disinfection and environmental remediation applications.